Insulating means suitable for use in handling high voltage power lines

ABSTRACT

Insulating means in the form of a rod to which tools can be attached for handling high voltage power lines. The rod is provided by a tube of insulating material which in its interior is divided into separate chambers or compartments by hollow pot members which are closed at one end and fit together within the tube.

United States Patent Roots 1 Aug. 29, 1972 INSULATING MEANS SUITABLE FOR USE IN HANDLING HIGH VOLTAGE POWER LINES Inventor:

England Assignee: St. Bernard Plastics Limited, Famborough Hampshire, England Filed: April 15, 1971 Appl. No.: 134,285

Foreign Application Priority Data April 16, 1970 Great Britain ..18,328/7O US. Cl. ..174/46, 16/116 R, 81/53.1, 156/172,156/185,156/192,174/138 D, 191/64, 287/126, 294/19 R Int. Cl ..B25g l/ Field of Search.174/ R, 5 SG, 45 R, 46, 138 R, 174/138 D, 177-179, 209, DIG. 4; /143 R, 143 B; 16/110 R, 116 R; 81/38, 53.1; 43/18 GF; 52/726; 156/172, 185, 187, 192, 294, 296;161/175,176,178;19l/60.5, 64; 287/126; 294/19 R, 206/65 K Philip Stanley Roots, Godalming,

[56] References Cited UNITED STATES PATENTS 906,157 12/1908 Porter ..206/65 K UX 2,841,634 7/1958 Kimball ..174/ R 2,997,529 8/1961 Fink ..174/138 D 3,178,018 4/1965 Bruun ..206/ K 3,469,338 9/1969 Hills ..43/18 OF FOREIGN PATENTS OR APPLICATIONS 227,678 9/1943 Switzerland 1 74/ 209 Primary ExaminerLaramie E. Askin Att0rneyMisegades & Douglas [57] ABSTRACT Insulating means in the form of a rod to which tools can be attached for handling high voltage power lines. The rod is provided by a tube of insulating material which in its interior is divided into separate chambers or compartments by hollow pot members which are closed at one end and fit together within the tube.

5 Claims, 1 Drawing Figure BACKGROUND OF THE INVENTION High voltage power lines are suspended upon insulators and in order to repair, replace or effect maintenance work on or in the vicinity of the insulators it is necessary to maneuver the power lines to positions in which they would not endanger the safety of an engineer engaged in such work 'while maintaining the power supply through the power lines. Means for maneuvering to and maintaining power lines in positions of safety are known. One type of known means includes an elongate rod provided by a tube of glass fiber reinforced synthetic resinous material which is filled with a polyurethane foam having a so-called closed cell structure. An elongate rod of this known construction can be used in a number of ways in handling high voltage lines. The rod may provide a handle for a tool mounted at one end of the rod which can be engaged with a power line by a maintenance engineer to lift the power line from seating engagement with an insulator provided therefor on, for example, a pylon. The same rod, or another rod of similar construction also having a tool mounted thereon can then be used as a support to anchor the power line in a position of safety, by clamping the rod, to, for example, the pylon, in a position such that the power line does not constitute a safety risk.

While insulating means in the form of elongate rods of the type described above have been used for high voltage work, it is believed that they may not be entirely satisfactory for very high voltage work essentially because of the nature of the polyurethane foam which may contain a proportion of open cells and may with repeated flexure of the tube during use thereof separate from the inner walls of the outer tube, thereby permitting moisture to infiltrate due to, for example, condensation of atmospheric moisture within the tube and/or the foam. This infiltration could result in a breakdown of the insulation provided by the rod.

OBJECTS OF THE INVENTION It is one of the objects of this invention to provide improved insulating means which can be-used in the handling of high voltage power lines.

It is another of the objects of this invention to provide a method of making the improved insulating means according to the invention.

BRIEF SUMMARY OF THE INVENTION The insulating means according to the invention comprises a hollow tube of insulating material, for example polyester resinous material or epoxy resinous material which may be reinforced with glass fiber (e.g. glass cloth or mat). Interior partition walls also of insulating material and arranged at spaced intervals along the length of the tube interior divide the tube into a plurality of closed spaces. In a preferred embodiment of the invention these partition walls are provided by bottom walls of elongate tubular pot members which are fitted together in spigot and socket fashion by engaging a base portion of one member in a mouth of the next adjacent member, and so on until the required length of tube has been built up. The so interfitted elements may then serve as a mandrel around which an outer sheath, preferably a continuous outer sheath, is formed, the outer sheath being bonded to the pot members as it is formed therearound.

The tubular elements may be substantially cylindrical in cross-section and are preferably of reduced cross-section at their base portions so as to interfrt in the fashion aforesaid. If desired the tubular elements may be secured, e.g., bonded to one another when interfitted, although this is not really necessary in all cases since they will automatically be secured together by the outer sheath when the outer sheath is formed therearound.

In carrying out a method according to the invention the individual pot members can be assembled together in a spigot and socket fashion as aforesaid and the hollow tube formed around the interfitted members. In carrying out a preferred method according to the invention the hollow tube is formed by wrapping glass fiber material impregnated with resinous material around the interfitted members and subsequently effecting curing of the resinous material under the infiuence of heat. Each of the pot members can be formed by injection moulding techniques or by wrapping glass fiber material impregnated resinous material around a mandrel of the required shape and subsequently effecting curing of the resinous material under the influence of heat.

The insulating means according to the invention may provide a handle having a tool permanently attached thereto or secured by one of a variety of known universal tool holders, e.g., of aluminum whereby any one of a number of different tools can be removably attached to the handle.

Alternatively insulating means according to the invention may provide a support for a permanently attached tool or for a detachable tool holder, which support can be clamped to, for example, a pylon or a pillar carrying overhead power lines to maintain a power line in a position of safety such that a maintenance engineer can operate in safety on or in the vicinity of insulators mounted on the pylon or pillar.

The insulating means according to the invention may be produced in any required length and of any required diameter, for use as a handle or other support, e.g., in lengths of from 8 to 20 feet and with diameters of from 1% to 3 inches.

Under test conditions it has been found that insulating means according to the invention was entirely satisfactory in carrying out high voltage work.

DESCRIPTION OF THE DRAWINGS The drawing is a perspective view, partly in crosssection, of insulating means according to the invention in the form of a short length handle for manipulating a tool for use in handling high voltage power lines.

Referring to the drawing it will be seen that the bandle 1 comprises a hollow tube providing an outer sheath 2 formed around and bonded to a series of interfitted cylindrical tubular elements in the form of pots 3 so that the hollow interior of the handle is divided at intervals along its length by the base discs 4 of the pots 3 into a series of closed spaces or chambers. Both the sheath 2 and pots 3 are made of suitable insulating material, e.g., glass fiber reinforced synthetic resinous material such as polyester resinous material or epoxy resinous material. Each of the pots is formed by moulding the glass fiber reinforced synthetic resinous material on a mould and effecting curing of the resinous material by heating. Alternatively each pot can be formed by injection moulding of a suitable synthetic resinous material.

A base portion of each pot 3 is of smaller diameter than the remainder thereof and is adapted to fit tightly into a mouth 6 of the next adjacent pot 3.

The handle 1 is made in carrying out a method according to the invention by assembling a series of pots 3 by inserting the base end 5 of each pot member into the mouth 6 of another pot member to form a mandrel and then forming the outer sheath 2 around and bonding it to the so formed mandrel. V

The outer sheath 2 is formed by wrapping glass fiber material impregnated with resinous material around a series of interfitted pots 3 and effecting curing of the resinous material by heating.

A known tool holder, e.g., of the universal kind above described, may then be attached to the handle 1 for the reception of various tools.

in use, the handle 1 may for example have a tool rigidly secured upon an end portion thereof which tool is substantially fork-shaped for engaging a power line. An engineer can with the handle manipulate the tool to lift a power line from an insulator upon which the power line is seated and transfer the power line to a position of safety so that maintenance work can be carried out in safety on or in the vicinity of the insulator.

I claim:

1. A substantially rigid electrical insulating pole for use in handling high voltage power lines,'comprising a plurality of elongated tubular pot members of electrical insulating material, said tubular pot members each having a closed base portion and a mouth portion and being assembled spigot-and-socket fashion with the base portion of one member engaged in the mouth portion of an adjacent member, and an outer sheath of electrical insulting material around said assembled pot members and adhesively secured thereto.

2. A pole according to claim 1, wherein each pot member comprises a hollow tubular body portion having an open end providing said mouth portion and a closed end providing said base portion, the base portion having an external diameter substantially according with the internal diameter of the mouth portion.

3. A pole according to claim 1, wherein the electrical insulating material from which said tubular pot members are formed is a synthetic resinous material reinforced with glass fiber material.

4. A pole according to claim 1, wherein said outer sheath comprises glass fiber material which has been impregnated with synthetic resinous material and which has been wrapped around the assembled pot members.

5. A pole according to claim 4, wherein said synthetic resinous material is a therrnosetting resin. 

1. A substantially rigid electrical insulating pole for use in handling high voltage power lines, comprising a plurality of elongated tubular pot members of electrical insulating material, said tubular pot members each having a closed base portion and a mouth portion and being assembled spigot-and-socket fashion with the base portion of one member engaged in the mouth portion of an adjacent member, and an outer sheath of electrical insulting material around said assembled pot members and adhesively secured thereto.
 2. A pole according to claim 1, wherein each pot member comprises a hollow tubular body portion having an open end providing said mouth portion and a closed end providing said base portion, the base portion having an external diameter substantially according with the internal diameter of the mouth portion.
 3. A pole according to claim 1, wherein the electrical insulating material from which said tubular pot members are formed is a synthetic resinous material reinforced with glass fiber material.
 4. A pole according to claim 1, wherein said outer sheath comprises glass fiber material which has been impregnated with synthetic resinous material and which has been wrapped around the assembled pot members.
 5. A pole according to claim 4, wherein said synthetic resinous material is a thermosetting resin. 